从 2 个下拉列表获取值的控制器操作

本文关键字：控制器 操作 获取 下拉列表 | 更新日期: 2023-09-27 18:34:24

我有一个操作家庭控制器，它从 2 个下拉列表获取参数。我的目标是保留每个 dropDownList 中的选定值，以便无论何时调用操作，都会定义这两个参数。我的问题是，每次我为其中一个选择新值到下拉列表时，另一个的值都会重置。

控制器： 

public ActionResult Results ( int? PageSize,int? RaceId, int page = 0)
        {                      
            ///code that uses PageSize and RaceId to get data from DB             
        }
public ActionResult _SelectRaces(int id=3)
        {          
            var results = db.Races.Where(r => r.Event_Id == id);
            if (results == null)
            {
                return HttpNotFound();
            }
            List<SelectListItem> items = new List<SelectListItem>();
            foreach (var r in results.ToList())
            {
                items.Add(new SelectListItem { Text = r.Name, Value = r.id.ToString() });
            }
            ViewData["Race"] = items;
            return PartialView(results.ToList());
        }
public ActionResult _SelectPageSize()
        {
            List<SelectListItem> items = new List<SelectListItem>();
            items.Add(new SelectListItem { Text = "5", Value = "5" });
            items.Add(new SelectListItem { Text = "10", Value = "10" });
            items.Add(new SelectListItem { Text = "25", Value = "25" });
            ViewData["PageSize"] = items;
            return PartialView(items);
        }

视图：

_SelectRaces.cshtml

@using (Html.BeginForm())
{
    <fieldset>
        Select Race
        @Html.DropDownList("RaceId", ViewData["Race"] as List<SelectListItem>, new { style = "width: 150px;", onchange = "this.form.submit()" })
    </fieldset>
}

_SelectPAgeSize.cshtml

@using (Html.BeginForm())
{
    <fieldset>
        Select Page Size
        @Html.DropDownList("PageSize", ViewData["PageSize"] as List<SelectListItem>, new { style = "width: 50px;", onchange = "this.form.submit()" })
    </fieldset>
    ViewBag.PAge = "Page";
}

Index.cshtml

    @Html.Action("_SelectPageSize")<!--Select Page Size-->
    @Html.Action("_SelectRaces") <!--Select Race-->
    @Html.Action("Results")

从 2 个下拉列表获取值的控制器操作

在这种情况下，

我使用了视图模型和部分视图：

例：

索引视图模型.cs

public class IndexViewModel
{
    public IList<SelectListItem> Races { get; set; }
    public int raceSelected { get; set; }
    public IList<SelectListItem> PageSize { get; set; }
    public int pageSizeSelected { get; set; }
}

在控制器中：

public ActionResult Index()
    {
        var results = db.Races.Where(r => r.Event_Id == id);
        if (results == null)
        {
            return HttpNotFound();
        }
        var items = new List<SelectListItem>();
        foreach (var r in results.ToList())
        {
            items.Add(new SelectListItem { Text = r.Name, Value = r.id.ToString() });
        }
        var pageSizes = new List<SelectListItem>();
        pageSizes.Add(new SelectListItem { Text = "5", Value = "5" });
        pageSizes.Add(new SelectListItem { Text = "10", Value = "10" });
        pageSizes.Add(new SelectListItem { Text = "25", Value = "25" });
        var model = new IndexViewModel()
        {
            Races = items,
            PageSize = pageSizes
        };
        return View(model);
    }

在您的索引中：

   @this.model IndexViewModel
     @{ Html.RenderPartial("_SelectPageSize", this.Model); }<!--Select Page Size-->
     @{ Html.RenderPartial("_SelectRaces", this.Model); }    <!--Select Race-->
     @{ Html.RenderPartial("Results", this.Model); }

_SelectRaces.cshtml（example） 和_SelectPAgeSize：

@this.model IndexViewModel
    <fieldset>
            Select Race
            @Html.DropDownListFor(x=>x.raceSelected, this.model.Races, new { style = "width: 150px;", onchange = "this.form.submit()" })
        </fieldset>

在提交方法中

    public ActionResult Results (IndexViewModel model)
            {   
var raceId = model.raceSelected;
var pageSize = model.pageSizeSelected; 
                ///code that uses PageSize and RaceId to get data from DB             
            }
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